The striker, signed from Celtic this summer, took a blow to the shin while making his first start for City in a 2-0 victory at Carrow Road.
And Chris Hughton afterwards said he was hopeful the results of a scan would clear Hooper of serious injury.
"Gary has been taken for a precautionary X-ray," he said. "He got a whack on the shin, it was an awkward challenge.
"We'll wait and see what the X-ray shows but hopefully it's just a whack which will be a bit sore rather than anything more serious."
City's victory over the Greek side came courtesy of two goals from Bradley Johnson, the first a header from Robert Snodgrass' early free-kick.
Johnson's second came in similar fashion after half-time, Javier Garrido providing the ammunition this time with a left-wing cross.
Before the game Hughton named last season's player of the year Sebastien Bassong as his new captain following Grant Holt's summer departure.